A New Approach for Determining the Minimum Concentration of Proanthocyanidin for Preservation of Collagen in H Dentin

Purpose: Introducing a minimum concentration and clinically relevant application time for grape seed extract (GSE) proanthocyanidin as a dentin preserver. Materials and Methods: Dentin beams were demineralized in 10% phosphoric acid for 24h. Then, the following groups were prepared: G1: no treatment, G2: 2% CHX + 1min, G3: 1% GSE + 1min, G4: 1% GSE +5min, G5: 2% GSE + 1min, G6: 2% GSE + 5min, G7: 5% GSE + 1min and G8: 5% GSE + 5min. After 30 days, MALDI-TOF mass spectrometry was used to confirm the availability of digested peptide fragments and monitor the pattern of collagen digestion. Gravimetric assessment and HPLC-UV were utilized for quantitative measurement of dentin destruction. Glycine quantities were considered as measures of collagen digestion. Results: 7% to 25% loss of dry mass was measured in experimental groups. Regarding the liberated Glycine, GSE dose- and time-responses were observed, so that, 5% GSE showed considerable protecting effect on collagen compared to 1 and 2% GSE (P<0.001) and 5min GSE application could establish superior dentin preservation compared to 1min application (P<0.001). Conclusion: 5-minute treatment of dentin at 2% GSE and above is essential for protecting the demineralized dentin collagen against biodegradation.

Collagen Dentin Matrix Metalloproteinase Proanthocyanidin Maldi-Tof Mass Spectrometry